A、Their lifestyles. B、Climate change. C、Natural disasters. D、Their great wealth. A新闻中提到，报告称，这10％的最富人口所选择的生活方式意味着他们的平均碳排放量是占全球人口一

The world’s richest 10% are responsible for half of all carbon emissions, according to a new report from aid and development charity Oxfam. The report, entitled "Extreme Carbon Inequality" was released during the crucial COP21 climate summit being held in Paris.
     (l)The lifestyle choices of the richest tenth of the population mean they have on average 11 times higher carbon footprint than the poorest half of the world’s population, the report said. The poorest half— roughly 3.5 billion people—is responsible only for 10% of emissions.(2)Yet they are the most affected by natural disasters attributed to climate change, such as flooding or droughts.
    The report says 64% of global emissions are the result of individual consumption. Richest people buy the most goods, and consequently are responsible for more pollution.
1. What caused the world’s richest 10% to produce so much carbon emissions?
2. What can we learn about the poorest half of the world’s population?